package com.gpframework.common.utils;


import cn.hutool.core.codec.Base64;
import com.gpframework.common.constant.BrandConstants;
import lombok.extern.slf4j.Slf4j;

import javax.crypto.Cipher;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESedeKeySpec;
import javax.crypto.spec.IvParameterSpec;
import java.security.Key;

/**
 * 带偏移量的3DES加密
 *
 * @author zcl
 */
@Slf4j
public class ThreeDES2Utils {
    // 密钥
    private final static String secretKey = BrandConstants.secretKey;
    // 向量
    private final static String iv = BrandConstants.iv;
    // 加解密统一使用的编码方式
    private final static String encoding = "utf-8";

    /**
     * 3DES加密
     *
     * @param plainText 普通文本
     * @return
     * @throws Exception
     */
    public static String encode(String plainText) {
        try {
            Key deskey = null;
            DESedeKeySpec spec = new DESedeKeySpec(secretKey.getBytes());
            SecretKeyFactory keyfactory = SecretKeyFactory.getInstance("desede");
            deskey = keyfactory.generateSecret(spec);

            Cipher cipher = Cipher.getInstance("desede/CBC/PKCS5Padding");
            IvParameterSpec ips = new IvParameterSpec(iv.getBytes());
            cipher.init(Cipher.ENCRYPT_MODE, deskey, ips);
            byte[] encryptData = cipher.doFinal(plainText.getBytes(encoding));
            return Base64.encode(encryptData);
        } catch (Exception e) {
            log.error(e.getMessage());
        }
        return null;
    }

    /**
     * 3DES解密
     *
     * @param encryptText 加密文本
     * @return
     * @throws Exception
     */
    public static String decode(String encryptText) {
        try {
            Key deskey;
            DESedeKeySpec spec = new DESedeKeySpec(secretKey.getBytes());
            SecretKeyFactory keyfactory = SecretKeyFactory.getInstance("desede");
            deskey = keyfactory.generateSecret(spec);
            Cipher cipher = Cipher.getInstance("desede/CBC/PKCS5Padding");
            IvParameterSpec ips = new IvParameterSpec(iv.getBytes());
            cipher.init(Cipher.DECRYPT_MODE, deskey, ips);

            byte[] decryptData = cipher.doFinal(Base64.decode(encryptText));

            return new String(decryptData, encoding);
        } catch (Exception e) {
            log.error(e.getMessage());
        }
        return null;
    }

    public static void main(String[] args) {
        String encode = encode("321");
        log.info(encode);
        String decode = decode("pfogrAk1qfc=");
        log.info(decode);
    }
}
